The current resize with modifier keys functionality exposed through the settings "Window Snapping and Moving > Moving and Resizing Modifier Keys" pane always resizes by only moving the location of the lower-right corner of the window. It would be preferable if the corner (or side) chosen was based on where the mouse was located. In other words, if the mouse is in the upper right part of a window, then the resizing operation should cause the upper-right corner's location to be modified, not the lower-right. The same should be true for other mouse locations relative to a window. Please consider making this either the default or at the least an optional behavior of this feature. Thanks!
This is not possible given the currently available macOS API's unfortunately.
See https://community.folivora.ai/t/resize-window-below-cursor-only-resizes-from-bottom-right/10976for some (not very good) workarounds.